UK nearing final stages of deal for E-7 Wedgetail aircraft

The UK is in talks with Boeing to replace its fleet of ageing E-3 Sentry aircraft with E-7 Wedgetail aircraft.

The Financial Times reported here on Tuesday that the decision is expected to be confirmed ahead of a NATO conference this week.

The Chairman of the Defence Committee had earlier written to the Minister of Defence Procurement to request that any requirement for replacing the Sentry aircraft be put out to a competitive tender, rather than bought ‘off the shelf’ with no competition taking place.

AWACS aircraft perform an important function on operations, providing long-range early warning and surveillance capability alongside airborne battle management and communications relay functions. The Royal Air Force possesses six Boeing E-3D Sentry AWACS aircraft. They are currently due to stay in service until 2035, subject to a capability sustainment programme to extend their service life. Reports have emerged however that as part of the Modernising Defence Programme, the Ministry of Defence is considering cancelling the sustainment programme and replacing the Sentry fleet with a new aircraft.

In its letter the Committee criticises the Sentry fleet’s poor state of maintenance. The readiness and number of flying hours completed by aircraft have been reducing, and the Committee has heard anecdotal evidence that only one of the six E-3D aircraft is available for service at any one time.

On the possibility of Sentry being replaced with a new system, the letter notes the advantages of a competitive tender in terms of maximising value for money and allowing proper consideration of a range of alternatives. The Committee also considers that a competition is particularly appropriate in this case, as there are viable alternatives available which deserve to be given fair consideration.

Defence Committee Chairman Dr Julian Lewis MP said:

“AWACS is an important capability for the UK to maintain, particularly given the possibility of future conflict taking place in a heavily contested airspace against peer adversaries. The fact that the capacity of the RAF’s current AWACS fleet has been run down to such a low level is greatly to be regretted.

The Ministry of Defence, if it seeks to replace Sentry with an entirely new system, has the opportunity to regenerate this capability and to give proper consideration to the range of available alternatives through a competitive tender. The benefits of doing so are clear, and this is exactly the kind of engagement that the Department should be seeking with industry in its drive to modernise Defence.”

However despite this, the first three Royal Air Force personnel arrived in Australia last month for training on the RAAF’s E-7 Wedgetail aircraft.

According to the Australian Defence Magazine, three RAF crewmembers, comprising a pilot, an Electronic Support Measures Operator (ESMO), and a Surveillance and Control Officer began their Wedgetail conversion course with 2 Sqn at Williamtown about three weeks ago.

“Number 2 Squadron has just taken on-board some trainees, both from the UK and the US – both pilots and back end mission crew,” 2 Sqn Senior Engineer Officer (SENGO) Squadron Leader Shane Taylor said at RAAF Base Tindal last week. “They will be progressing through the training continuum over the coming twelve to eighteen months and certainly other countries are expressing an interest in this capability.”

They say that the news follows the recent demonstration of the Wedgetail’s capability at RAF Waddington, home of the RAF’s Sentry fleet. One aircraft attended the Royal International Air Tattoo at RAF Fairford in July and deployed to Waddington after the show to demonstrate its capabilities to the UK’s Sentry force.

The E-7A Wedgetail provides one of the most advanced air battlespace management capabilities in the world and the Royal Air Force are rumoured to be interested in it to replace their E-3D Sentry aircraft. The aircraft is an Airborne Early Warning & Control aircraft with maritime search capabilities, it has the ability to control unmanned aircraft and it has intelligence gathering capabilities.

We recently reported that options for the future delivery of the UK’s Airborne Warning and Control capability are being explored, with the focus now on replacing the E-3D Sentry fleet.

We understand that upgrades however are reportedly considered to be expensive. According to Janes here, maintenance is becoming increasingly costly and replacing them instead might be the most cost-effective option.

Some industry commentators are also arguing for a new aircraft type altogether. The large sums of money allocated to upgrading the E-3D fleet should be used to purchase a more advanced off-the-shelf aircraft, a defence analyst has argued. Justin Bronk, Research Fellow, Airpower and Technology, outlines options for replacing the E-3 fleet in his paper ‘The Future of Air C2 and AEW: E-3 Sentry, Threat Technologies and Future Replacement Options’:

“The RAF’s E-3Ds need a £2-billion CSP both to bring them to rough parity with current US and French standards by the mid-2020s and to stretch the fleet out to 2035 in the process. However, the E-3, even in modernised form, is no longer a cutting-edge ABM&S system in a world where proliferating long-range missile systems and emerging non-Western low-observable fighters can force it to stay hundreds of kilometres from contested airspace, placing a higher premium on BLOS communications capacity rather than onboard sensors.

Even when it is able to operate closer to the battlespace, the AN/APY-1/2 mechanically scanned radar array common to all E-3s has significant inherent limitations in terms of its ability to detect low-observable, very slow moving and hypersonic threats, unlike more modern AESA-equipped AWACS types already in service with the US Navy and various air forces around the world. An AESA-equipped ABM&S platform with improved communications node capabilities, based on a commercial-derivative airframe, seems a logical alternative option which could provide the RAF with a more capable and efficient alternative to extending the life of the E-3D over the next 20 years.”

Both the Sentry and Wedgetail are designed to monitor airspace to provide threat detection of adversary aircraft and situational awareness on friendly assets.

The E-7A Wedgetail is based on a Boeing 737-700, with the addition of an advanced Multi-Role Electronically Scanned Array (MESA) radar and 10 mission crew console. They can cover four million square kilometres during a single 10 hour mission according to the Royal Australian Air Force.

“The E-7A Wedgetail represents an entirely new capability for the Australian Defence Force, providing an airborne early warning and control (AEW&C) platform that can gather information from a wide variety of sources, analyse it and distribute it to other air and surface assets.

The E-7A Wedgetail can control the tactical battle space, providing direction for fighter aircraft, surface combatants and land based elements, as well as supporting aircraft such as tankers and intelligence platforms. Based on the 737-700 commercial airliner airframe, the E-7A Wedgetail features advanced multi role electronically scanned radar and 10 state-of-the-art mission crew consoles that are able to track airborne and maritime targets simultaneously.”

As the Second Line of Defense put it, the Wedgetail is designed with ‘the reach rather than range approach’; the MESA radar can be dialled up in terms of energy and focused in terms of direction on priority scan areas. As one Northrop Grumman engineer reportedly put it:

“There is a fundamental shift operationally in terms of how one uses the Wedgetail versus the AWACS. You no longer are limited or defined by a 360 degree rotator. You are able to configure how much power you want to put into your radar reach; it is configurable to the mission. The integrated IFF and radar functionality also allows the system to reach much greater than other systems into the battlespace to shape greater situational awareness in the battlespace. You can put the energy in the mission area where you have the highest priority.”

The (aptly named for a potential British purchase) ‘Top Hat’ of the aircraft houses the radar.

The L-band electronically scanned AEW and surveillance radar is located on a dorsal fin on top of the fuselage, dubbed the “top hat”, and is designed for minimal aerodynamic effect.

The system provides 360 degree coverage and is capable of simultaneous air and sea search, fighter control and area search, with a maximum range of over 600km (look-up mode). When operating in look-down mode against fighter-sized target, the maximum range is in excess of 370 km according to Boeing. When used against maritime targets, the maximum range is over 240km for frigate-sized targets. MESA is capable of simultaneously tracking 180 targets and conducting 24 intercepts. Back in 2009, Boeing even demonstrated control of three ScanEagle unmanned aircraft from a Wedgetail.

Wedgetail looks to be maturing nicely in Australian hands with the major early teething troubles now ironed out. It’s also currently undergoing a major programme of further upgrades, due to be completed in 2022 that we reported on here.

Back in 2014, a Wedgetail conducted the first Australian sortie over Iraq supporting coalition forces conducting airstrikes against Islamic State. The next year, another performed the longest Australian command and control mission in a war zone during a 17-hour, 6-minute combat mission, requiring two air-to-air refuellings to stay aloft.

Photo by Bidgee [CC BY-SA 3.0], from Wikimedia Commons.What we don’t know however is how closely the Wedgetail matches what the Royal Air Force want from an E-3D Sentry replacement but the degree of commonality with P-8A Posiedon Maritime Patrol Aircraft being purchased can’t be a bad thing, especially when Wedgetail also has an enhanced maritime search capability which may be useful in augmenting the relatively few P-8s being purchased.

Hi Daniele MDP will deliver just that, it will be marketed as modernisation – something I have no problem with as long as those that win are the men and women in the military and the platforms they get given to generate military effect, the sharp edge of government policy. What we have now is the classic battle between the Treasury and the MoD. Treasury have a point, the MoD waster huge amounts of money with no accountability, cannot spend all their allocated money in year (an easy way to highlight this is manpower against requirement, you cannot pay who you don’t “employ”). MoD need to demonstrate that they can spend money better, get more value for money for the tax payer and give something to the military, on time, meeting the requirement and to budget. All to often ministers get dazzled by the latest toy and their need to show that they are supporting industry by buying British or buying the latest fad. Treasury need to relax their spending review model and adapt to the changing situation, move away from in year spending limits – forcing the department to spend its budget in the fear that if its not spent in year it is lost from next year. The department settlement should take into account the amount of time it takes to take a product through the gate process and provide flex, it can do that without increasing the budget allocation. The MoD can help by making SRO’s responsible for the whole life cycle of a procurement, not just the two years they are in post before being moved on – they become more accountable, they have a vested interest in the capability and can see it through until at least main gate or SDR3/4 – “Is the design mature enough to be put in to production with lowest possible risk”. This however changes the culture, which is extremely difficult in a department that feels it needs to protect itself from treasury, where those (not all) who allocate the spend can sometimes end up with working for the very company that has been awarded the contract. When you have a department who’s spend is mostly allocated to the comapanies and businesses that support defence that will be a hard thing to change.

MDP will show whether real change is afoot, where pain will be endured as some capabilities – close to the hearts of some will be removed and replaced by others that are not fully understood and cannot be counted like aircraft on the flight line or tanks in a Sqn. Or will it display another fudge where some new shiny toys, like Wedgetail are lauded, but capability to fight is lost in the noise.

We hope that there are those in defence who recognise that the latter cannot go on and that, whilst tough decisions need to be made (reduction in T23, removal of legacy armoured platforms and re-rolling of units), the benefits in the longer term, against a slightly increased GDP % increase will out weigh the short term pain that we are going to feel

If the RAF goes ahead with the Wedgetail, it will be yet another RAF platform that was designed for boom refuelling. So is there also a budget to either enhance the Voyagers with boom refuelling capabilities, or pay for the R&D associated with adding a probe to the Wedgetails?

(Chris H) TwinTiger – The nose and front fuselage of a 737 is almost identical to the 707 (or rather ‘Dash – 8’) and our Sentry aircraft have drogue and probe refuelling. There is no technical or safety reason why Boeing could not build such a system into Poseidons or Wedgetail on the FAL. And if they can’t or won’t then I am sure Marshalls and Cobham here in the UK could do it. Its already been done so no ‘R & D’ is required. Just political will and telling Boeing who the customer is.

Thanks Chris, You make it sound so simple! I’m glad that you believe that this will not be an issue. Sadly, the lack of a boom on the Voyagers is a major oversight for interoperability and future-proofing, IMO, that will be brought into sharp relief if the Wedgetails are indeed purchased.

… Just to add, I can’t recall reading that the RAF Poseidon fleet were also going to be fitted with probes? If not, surely refitting the Voyagers with a boom would be more cost effective that adding all those probes to RAF military versions of the 737s that were designed without them? Just saying …

Any idea how much the MOD saved by removing the probe? I agree it was a bit short sighted especially when it would have been useful for interoperability with the US. Maybe it was fitted for but not with a boom (to save maintenance costs) in which case it should not be difficult to upgrade the MRT fleet.

Chris the nose and front fuselage of the 737 is derived from the 707 but to say there is no technical or safety barriers to adding a probe to the former is absurdly naive and very ignorant of history. There is significant difference between these aircraft and I suggest you have a look at the ‘Haddon Cave’ report before making such simplistic assertions.

Many decades separate the 707-320 that the E3D is built upon and the E-7 and P-8 variants of the 737. There is actually a fair amount of difference between the E-7 and P-8 making them in effect unique sub variants themselves. It certainly isn’t just a case of taking the E3D probe installation and dropping it onto the E-7 and P-8, it will require redesign and certification with support of Boeing. Boeing will charge significant amounts of money to do that and the in service date of both types would be severely delayed!

If Boeing can’t or won’t do it then forget about just handing it off to Marshall’s or Cobham to just jump in and throw a solution on! Boeing holds the type certificate for both types and in our post ‘Haddon Cave’ world there is ZERO CHANCE of non-oem supported additions getting the appropriate safety case through!

Even without ‘Haddon Cave’ there is NO WAY that the MOD is going to repeat the Chinook MK.3 debacle! Just to remind you that cost the UK tax payer hundreds of millions of pounds with brand new airframes undelivered for nearly 20 years because the MOD attempted a home-brew software upgrade without Boeings support. The aircraft then couldn’t get a release to service as the changes made to the software could not be guaranteed as safe. Eventually Boeing were paid to install the avionics from the Chinook Mk.2 just to get them in service!

That was just a Software change, designing and installing a probe based refuelling system without Boeing support is a total non-starter!

Hi Not quite true on the Mk3 Chinook shambles but you are correct on the outcome – of which no accountability was atributed, the MoD got away with wasting £230m. Options were available to MoD from the outset on those aircraft, return to vendor, sell to UAE or field direct to Afghanistan – not of those options were taken up, it would have admitted culpability and someone would have to take the blame, that is not the way things are done. Always remember these aircraft were purchased against an SF requirement, if anyone knows how our SF work they like to blend in and disappear – this aircraft, on arrival looked nothing like the Mk2 fleet fielded by the RAF. So they sat in a hangar in Philadelphia whilst the MoD worked out what to do with them. You cannot fly aircraft in the U.K. unless the CAA can see the source code of the firmware of the flight control systems used to manage the aircraft, an ITAR would have solved that problem – one was not requested, £230m due to a box not being ticked. Happy to discuss further. Remember, after the digital cabling was ripped out of those aircraft and replaced with 1970’s dials they were sent to Fleetlands to have digital flight decks and cabling installed under Project Julius, sometimes you just cannot make these things up

(Chris H) fedaykin – and if you are referring to the software / access password cock up on Chinooks again I fail to see the relevance to a refuelling system that would be built in to an aircraft on a production line.

Not sure equating Cobham (whose business is supplying and fitting refuelling systems all over the world) to a lack of software knowledge by the MoD on Chinooks makes your point very well either.

(Chris H) Fedaykin – Why are you conflating a crash judged to be pilot error (rightly or wrongly) to a manufactured refuelling system? They are in no way similar! I agree the MoD / RAF made a pigs ear on maintenance on Chinooks and Nimrods and one knowledgable and experienced engineer was quoted as saying: “[reports] revealed a period of “neglect” during the 1990s culminating in lower staff levels and experience, inadequate training, over flying, failure to investigate faults, out-dated publications and poor communication”

Utterly shameful but that failure to maintain aircraft has no bearing on a refuelling system fitted in a new airframe. And you accuse me of being ‘simplistic’?

There is also a world of difference between converting an aircraft in service from one system to another and building a new system into a brand new airframe on the production line. Or have I missed something? I won’t trail my CV but I am not plucking stuff off of Google or Wiki here.

And yes I do know there will be detailed differences between a 737 (Poseidon) and a Dash 8 (Sentry) front fuselage but my point (maybe badly made) was that the external shape is similar and therefore we know safe operation can be made using Drogue and Probe refuelling systems. And again I just do not see where Boeing cannot (given we are the customer) add this to a Poseidon aircraft during build. After all the Boom receptacle is exactly where the Probe would exit the fuselage is it not? Pipework and safety systems are already in that fuselage so we are discussing the change to externals and nothing else.

Evening Thread didn’t go quite where I expected but WRT the probe. It would be easier to adapt the A330 or, through contract amend the support model to include a boom set, they are being built for other customers and the RAF could save face by stating that at the time of purchase it was not known what aircraft would be purchased to replace Nimrod and Sentry and on a balance of investment saving money for the taxpayer it was decided to go fro the lower risk option. Adding a boom also means updating the training and operation of the aircraft, This takes time. Also remember these are commercial frames, adding a probe down the centre line of the aircraft will result in delay. Nothing is impossible, it just takes time and money.

(Chris H) Lee H – the A330 MRTTs we have that are ‘KC.Mk 3′ aircraft have fuselage centreline drogue systems. This is the location for the ARBS (Airbus’ boom system) and as I understand it the airframes are passively engineered for ARBS fitment.

Having said that I still argue it is simpler and less expensive (and operationally less restrictive) to have all our aircraft as ‘Drogue and Probe’. We only have 8 C-17 Globemasters, 3 RC-135 Rivet Joint not fitted with Probe refuelling. All are very long range anyway. So I am not sure the business case stacks up.

And if Lockheed and Cobham can safely retro – fit C-130 Hercules and Airbus can fit from new A400M Atlas with probes why can’t Boeing for our Poseidons?

Again having said that we are dealing with the MoD who seem to not understand that we are the customer and Boeing is the supplier.

Well looking through your reply only affirms my general view that you haven’t a clue what you are talking about Chris along with your usual windbaggery!

Firstly you have mixed up the Mull of Kintyre Chinook report with ‘Haddon Cave’ the report into the loss of Nimrod XV230. Further from that ‘Haddon Cave’ does not just focus on poor maintenance, it is a scathing review of the entire UK military Air worthiness system. A large proportion of the findings directly attack the activity of bodging in features and systems without proper OEM support and need I remind you a major cause of the XV230 crash was flaws in the air to air refuelling system bodged into the Nimrod.

The direct result of ‘Haddon Cave’ was a complete overhaul of the release to service process for an aircraft and how a safety case is defined. Your suggestion that if Boeing doesn’t play ball by adding a probe to one of their types then Marshall’s or Cobham should just be asked to step is utter nonsense in the current regulatory environment. MAA will not sign it off period!

“I won’t trail my CV but I am not plucking stuff off of Google or Wiki here.” – I am sure you are not checking Google or Wikipedia because they would at least offer corrections to what you have been incorrectly asserting.

“Again having said that we are dealing with the MoD who seem to not understand that we are the customer and Boeing is the supplier.” –

Yet again just the same as with T31 you are going down the Rabbit hole of your own thinking that if we just demand that industry do something harder then they shall do it with no impact or cost.

“And yes I do know there will be detailed differences between a 737 (Poseidon) and a Dash 8 (Sentry) front fuselage but my point (maybe badly made) was that the external shape is similar and therefore we know safe operation can be made using Drogue and Probe refuelling systems.” –

Well that makes me glad that you have nothing to do with Airworthiness! Without out detailed testing and modeling we won’t know that. Maybe it is simple branching off the plumbing for the receptacle but without OEM support, testing and paperwork UK MAA will not release to service.

I am certain that yes Boeing could develop a probe based solution for both aircraft but it will increase the cost and delay the service entry. In the end it is a trade off, we will used allied tanker support for the moment and if we suddenly need the capability to self refuel these aircraft my guess is we will go down the quicker and safer certificated route of putting the boom on the Voyager tankers.

(Chris H) fedaykin – Quote: “Well looking through your reply only affirms my general view that you haven’t a clue what you are talking about Chris along with your usual windbaggery!”

So therefore I won’t waste your clearly valuable time any further and please forgive my temerity in trying to offer any opinions. I must learn that my position in this Forum is vastly inferior to superbly informed and experienced specialists like yourself.

What people seem to miss in boom versus drouge install for larger aircraft against fighters requirements is the fuel loads are considerable different. A large aircraft would certainly prefer the lesser hook up time derived from the flow rate delivered by the boom as apposed to the considerably slower rate from the drouge, which is quiet however suitable for fighters top up. It has to be remembered that the only reason probes were fitted to the likes of Nimrod, VC10, Belfast, C130 was that the drouge was the only delivery available via Victors and VC10 .

reminds me of a comment i made on an earlier article on Singapore’s acquisition…….. wtf were we the only county in the world to think not fitting the boom was a worthwhile cost saving…….. honestly it pisses me off that basically it boils down to accountants setting the requirements of what we end up with over what we actually need….. how short sighted is that looking now eh? and how much extra are we gonna end up paying to add the boom once we’ve realized our idiocy in the first place!

I’d read that 51 Sqns Nimrod R1s were particularly capable in ELINT as opposed to the SIGINT capability of the Rivet Joint that replaced them. The RAF was said to be losing a good standard capability in ELINT when the R1s were withdrawn.

Possible game changer there concerning replacement type chosen for the E3.

Speaking to the guys of 2 Sqn RAAF at this year’s RIAT, they said the decision to buy Wedgetail is a done deal according to them. We definitely missed the ball on this one. We had an airframe with at least 30 years life that could have been converted to AEW in the Airbus A330 Voyager. Admittedly the aircraft is a lot bigger than a B737, but then it would have the capacity for future growth or multiple uses i.e. blending Sentry’s AEW with Sentinel’s battlefield surveillance. We have the designers and engineers who could have developed an AESA radar along with the software processing. I am really surprised that the E3 operators never “publicly” investigated replacing the aircraft and its radar as a collaborative effort. The benefits that an airborne AEW platform bring to both offensive and defensive operations cannot be understated. They are both a force multiplier but also a deterrent and the countries that do not have such a system will always be less capable.

“The benefits that an airborne AEW platform bring to both offensive and defensive operations cannot be understated.”

Yes that is why we should have built the carriers around E2 and not the pointy fast bomb truck. I also fear that though Crowsnest will be good it might have been great if we had just spent a little more both on the system itself and the supporting hardware (brand new air frames for a start).

Yes, if not better. The Crowsnest is just an updated Thales Searchwater radar and Cerberus Mission System as fitted to the Sea Kings. I believe they’re having a new mechanical antenna array and new software for the mission system. So technically the range and resolution should be better than the previous system giving a much better picture over land.

Hate to burst your bubble but the DOD teied exactly that with a JSTAR & E-3 replacement and it never made it off the design stage. Having two powerful and different radars designed for different roles caused too much interference. You could have a radar that can do both roles but there would be compromises in its capabilities as it would have to be a secondary role.

The DOD tried that with a JSTAR & E-3 replacement combo and it didnt work. The idea of carrying 2 radars designed for different missions caused too much interference to make it out of the design stage.

The 707 airframe is maxed out and has been for quite a while. It’s time to replace them with a modern variant that can be supported and shares commonality with other systems to save money. I have heard rumors that the USAF is seriously considering an unmanned platform as the AWACS replacement with a downlink to the Air Battle Managers similar to current drone operations that would involve a modulized system that could be set up anywhere – including on navy ships or even in the cargo holds of transport aircraft. The advantage here is to avoid exposing the crews to the danger of being shot down by anti-radiation missiles – drones can be replaced. Highly trained crews cannot – I refer to the experience of the IJN carrier force and the Kido Butai during WWII in this…

Back in the Paleolithic period of Spec Ops (early 80’s) We would actually ride the rocket pod on the side of the Aircraft (straddling it and snaplinked inside because there was no room in the aft compartment of the gunships) ahead of the TF160 lift ships with the assault troops aboard – 1 would carry the FSO and I in that manner. Another would carry the (Ranger) company CO and his RTO.

As soon as we hit Terra Firma (usually the highest point in the target area) we would disembark, the FSO would start controlling the gunships and fires, I always had an “A” or “H” model Specter orbiting overhead and that was my purview. I can tell you that it was “highly” exciting to infill in such a manner. Blacked out, pitch dark, and wearing very early model PVS5 NVG with a 100knot slipstream battering you (It was worse for the FSO he was in front of me)… 😀

One of the main reasons that the Aussies are looking at the “Little Birds” are that they are easily air-transportable by Herc/C17. You can get at least two in a stretched Herc with all the support equipment and engineers etc. It only takes an hour to get them flight worthy. I believe the Yanks had it down to less than 30 minutes after landing. There has also been a development of converting the aircraft configured as a gunship to a remotely piloted vehicle.

Maybe it would be possible to order more P8 Poseidon with the 737-800 air frame and have the kit from the Wedgetail integrated into it. This means a common air frame across the fleet and with the weapons fit could attack targets of opportunity. Just an idea.